不等式恒成立的问题既含参数又含变量,往往与函数、数列、方程、几何有机结合起来,具有形式灵活、思维性强、不同知识交汇等特点。考题通常有两种设计方式:一是证明某个不等式恒成立,二是已知某个不等式恒成立,求其中参数的取值范围。解决这类问题的方法关键是转化、化归,通过等价转化可以把问题顺利 The problem of inequality constant is established, which contains both parameters and variables. It is often combined with functions, sequences, equations and geometry. It has the characteristics of flexible form, strong thinking, and convergence of different knowledge. There are usually two design questions: one is to prove that an inequality is constant, and the other is that an inequality is known and its value range is found. The key to the solution to such problems is to transform and return to normal, and the problem can be solved smoothly through equivalent transformation